Internal-combustion engine



Jun 15 1924. 1,480,609

- c. R. GREUTER L INTERNAL COMBUSTION ENGINE Filed Oct. 21, 1922 2 Sheets-Sheet 1 gwuenfoz 351; M an Jan. 15 1924. 1,480,609

7 ea, GREUTER INTERNAL-COMBUSTION ENGINE Fired Oct; 21, 19-22 2 Shouts-Sheet 2 Patented Jan. 15, 1924.

UNITED STATES CHARLES R. GREUTER, F CHICAGQILLINOIS.

INTERNAL-COMBUSTION ENGINE.

Application filed October 21, 192-2. Serial No. 596,012.

T 0 all whom it may come-m:

Be it known that I, CHARLES R. Qnno'rnn, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Internal-Combustion Engines. of which the following is a specificationI This invention relat'esto internal combustion engines ofthe poppet valve type and resides in means for silencing the action of the cam shaft at low engine speeds.

In all poppet valve engines, and particularly in those having four or fewer cyl.

i'nders, the thrust of I successive tappets against the cams imparts to theca-m shaft rotative impulses alternating 111 direction at low engine speeds. This causes a chattering noise, much of thisnoise occurring in the drive train between the crank shaft:

' and the cam shaft. The noise is particularly notice-able in engines having gear driven overhead cam shafts, and the noise tends to increase as the gears-wear because of the increased backlash. At higher engine speeds, the noise practically disappears because the increasedl'oadon the cam shaft precludes any chattering in the drive train.

Thepresent invention secures quiet running of the engine at idling speeds by ap plying an artificial or brake load to the cam shaft. This load is relieved at higher speeds. Various means might be used to release the brake at such higher speeds, but

I prefer, andillustrate in-tlie accompany-- ing drawings, a construction in which the brake is applied .by an adjustable spring mechanism and is releasedby a positively acting device so connected to the-throttle that the brake is disengaged by the initial opening" movement of the throttle and thereafter is allowed to engage only as the throttle is returned to idling position.

In the drawings:

Fig. 1 is a side elevation of a four-cylinder engine of the type having an overhead gear-driven cam shaft. showing my invention applied thereto. In this view, the cam shaft housing is partly broken away.

Fig. 2 is a section on the line 2-2 of Fig. 1.

Fig. Fig. 2.

Fig. Fig. 2.

3 is a section on the line 3-3 of 4 is a section on the line 44 of Referring first to Fig. 1, 6 represents a four-cylinder engine of any preferred con struction provided with an overhead cam shaft 7 The cam shaft 7 is provided with? inlet and exhaust cams 8, which, in the particular en ine illustrated, are arranged to act directy on the valve stems (not shown). The cam shaft 7 turns in bearings 9 and carries a, beveled gear 10 which is driven at the proper rate by a beveled pinion 11 The pinion 11 is mounted on a vertical shaft (not shown) and this shaft is driven in anyoonvenient manner from thecrank shaft f the engine, as is obvious to those skilled in the art. a

Referring now particularly to Figs. 2 to 4 inclusive, it will be observed that shaft .7

is provided with a brake-drum 12. Sur rounding the brake drum 12 is a brake band consisting of two sections 13 and L4 hinged together at 1-5 and drawn together So as to enter into frictional engagement with the drum 12 by meansof an adjustable spring device. This spring device assume various different forms. As shown, it includesa bolt '16, spring L7, spring seat 18 and two nuts 19 one of which acts as a check nut tol ck, the othen; The bolt 1.6 passes throughthe ends of the sections 13 and 14 of thebralge band and is surroundedbythe spring 17." v,

.The jspringlTbears at one end onthe seat 18 and at the other end on a seat formed in the brake band section 14. The sprir'ig seat 18, is held on the bolt 16 by. the nuts 19 and the efiective stress of the spring may be adjusted ,by adjusting the nuts 19. Thus, the spring urges the brake bands in a direction to engage the drum 12 and.the degree of such engagement may be 1i .mited by the adjustment. of the ;spring ,l7. The brake band structure as a whole is held against rotation by a lug 20 preferably formed integrally with the brake band section 14 and entering a socket or recess in a bracket 21, especially provided for that purpose, and bolted to the cylinder head 22, as is clearly shown in Fig. 2.

The entire cam shaft structure is enclosed within a housing 23, also bolted to the cylinder head ,22. Rotatably mounted in a bearing 24, attached to this housing, is a shaft 25. The inner end of the shaft carries a cam 26 of elliptical form, which enters between the ends of the brake band sections 13 and 14 and, when rotated from the position shown in Fig. 8, forces the brake band sections 13 and 14 apart against the resistance of spring 17, and hence releases the brake.

The outer end of the shaft 25 carries a lever arm 27 which is pivotally connected to a sleeve 28 (see Fig. 1). The sleeve 28 is longitudinally adjustable on a link 29 by means of nuts 30, 31. The carburetor of the engine is indicated at 32 and the shaft of the throttle valve at 33. A bell crank lever is fixed on the shaft 33 and one of its arms 34 is pivotally connected 'to the link 29. The other arm 35 of the bell crank lever is connected'by a link 36' to any suit able throttle actuating linkage; This linkage "may lead to ahand lever on the steering wheel of an automobile or to a pedal on the footboargl, or to both "t'he particular mode of connect-ion being immaterial.

The parts are so adjusted that, when the throttle shaft 33 is in such angular position that the engine idles at the proper speed, the

cam 26 will perm'it'th' brake band "sections 13 and 14 to engage the drum under the action of the spring 17. The intensity of such engagement m ay beadjusted by adj usting the'spring 17. Rotation of the shaft 33 ina direction to open the throttle Will result in a corresponding" rotation of the shaft 25 and cam 26 will consequently force the brake band sections apart and release the brake.

"The springTT 'is-so-"adjnsted as to exert the minimum stress on the brake bands which will prevent chattering of the gears l0 and 11, and the sleeve 28 is so adjusted that the brake will be; completely released as theengine reaches the speed at which the load on the cam shaft is sufficient to prevent chattering of the gears 10 and 11. This adjustment can readily be determined by lilla il'. i

Various other devices might 'be used to release the" brake as the engine speed rises, but I prefer the one shown because of its simplicity.

W hat is claimed is 1. Thecombination of an engine having a cam shaft; a releasable brake serving to oppose the rotation of the cam shaft; and a mechanism serving to apply "said brake when the engine idles and to release said brake at higher speeds.

2. The combination of an engihe including a cam shaft and a part which is moved as an incident to changes of engine speed; a releasable brake serving to oppose the rotation of the cam shaft; and connections between said brake and said movable part whereby the brake is applied at low engine speed and released at hi her speed.

3. The combination of an engine having a cam shaft; a throttle serving to control said engine; a releasable brake serving to oppose the rotation of said cam shaft; and connections between said brake and throttle whereby the brake is released by the initial opening movement of the throttle.

4. The combination of an engine havin a cam shaft; a throttle for controlling said engine; a brake acting on the cam shaft; a spring acting to apply said brake; and connections between said brake and throttle constructed and arranged to release said brake during the initial opening movement of the throttle.

5. The combination of an engine having a cam shaft; a throttle for controlling said engine; a brake actin on the cam shaft; a spring acting to app y said brake; means for adjusting the stress on said spring; and connections between said brake and throttle constructed and arranged to release said brake against the action of said spring during the initial opening movement of the throttle.

6. The combination of an engine havin a cam shaft; a throttle for controlling sai engine; a brake acting on the cam shaft; a spring acting to apply said brake; a cam constructed and arranged to release said bra'ke against the action of said spring; and connections between said cam and said throttle constructed and arranged to move said cam in brake releasing direction during the initial opening movement of the throttle.

In testimony whereof I have signed my name to this specification.

CHARLES R. GREUTER. 

